Fixed type errors in Karma configuration and added aliases for tests

tests/karma.conf.ts

@@ -22,7 +22,14 @@
 
 import * as path from "path"
 
-import { Config, ConfigOptions } from "karma"
+import {
+  Config as KarmaConfig,
+  ConfigOptions as KarmaConfigOptions
+} from "karma"
+import {
+  Configuration as WebpackConfig,
+  NewModule
+} from "webpack"
 
 /* ----------------------------------------------------------------------------
  * Plugins
@@ -34,48 +41,16 @@ import EventHooksPlugin = require("event-hooks-webpack-plugin")
  * Configuration
  * ------------------------------------------------------------------------- */
 
-export default (config: Config & ConfigOptions) => {
-  config.set({
-    basePath: __dirname,
-
-    /* Frameworks to be used */
-    frameworks: [
-      "jasmine",
-      "jasmine-diff",
-      "viewport"
-    ],
-
-    /* Entrypoint for tests */
-    files: [
-      "index.ts"
-    ],
-
-    /* Preprocessors */
-    preprocessors: {
-      "index.ts": [
-        "webpack",
-        "sourcemap"
-      ]
-    },
+export default (config: KarmaConfig & KarmaConfigOptions) => {
 
   /* Webpack configuration */
-    webpack: {
+  const webpack: Partial<WebpackConfig> = {
     module: {
       rules: [
-
-          /* TypeScript */
         {
           test: /\.tsx?$/,
           use: "ts-loader",
           exclude: /\/node_modules\//
-          },
-
-          /* Instrumentation for code coverge */
-          {
-            test: /\.tsx?$/,
-            use: "istanbul-instrumenter-loader?+esModules",
-            include: path.resolve(__dirname, "../src"),
-            enforce: "post"
         }
       ]
     },
@@ -83,7 +58,11 @@ export default (config: Config & ConfigOptions) => {
       modules: [
         path.resolve(__dirname, "../node_modules")
       ],
-        extensions: [".js", ".ts"]
+      extensions: [".js", ".ts"],
+      alias: {
+        "~": path.resolve(__dirname, "../src/assets/javascripts"),
+        "@mock": path.resolve(__dirname, "mocks")
+      }
     },
     plugins: [
 
@@ -100,8 +79,44 @@ export default (config: Config & ConfigOptions) => {
         }
       })
     ]
+  }
+
+  /* Instrumentation for code coverage */
+  if (config.singleRun)
+    (webpack.module as NewModule).rules.push({
+      test: /\.tsx?$/,
+      use: "istanbul-instrumenter-loader?+esModules",
+      include: path.resolve(__dirname, "../src"),
+      enforce: "post"
+    })
+
+  /* Karma configuration */
+  config.set({
+    basePath: __dirname,
+
+    /* Frameworks to be used */
+    frameworks: [
+      "jasmine",
+      "jasmine-diff",
+      "viewport"
+    ],
+
+    /* Entrypoint for tests */
+    files: [
+      "index.ts"
+    ],
+
+    /* Preprocessors */
+    preprocessors: {
+      "index.ts": [
+        "webpack",
+        "sourcemap"
+      ]
     },
 
+    /* Webpack configuration */
+    webpack,
+
     /* Reporters */
     reporters: config.singleRun
       ? ["spec", "coverage-istanbul"]
@@ -115,7 +130,7 @@ export default (config: Config & ConfigOptions) => {
       suppressSkipped: true
     },
 
-    /* Enable code coverage */
+    /* Configuration for coverage reporter */
     coverageIstanbulReporter: {
       reports: [
         "html",
@@ -123,7 +138,7 @@ export default (config: Config & ConfigOptions) => {
       ]
     },
 
-    /* Hack: TypeScript is served with "video/mp2t" mime type */
+    /* Hack: TypeScript files are served with "video/mp2t" mime type */
     mime: {
       "text/x-typescript": ["ts"]
     }

tsconfig.json

 {
   "compilerOptions": {
     "allowJs": true,
-    "allowSyntheticDefaultImports": true,
     "alwaysStrict": true,
     "baseUrl": ".",
     "emitDecoratorMetadata": true,
@@ -18,6 +17,10 @@
     "noImplicitReturns": true,
     "noImplicitThis": true,
     "noUnusedLocals": true,
+    "paths": {
+      "~/*": ["src/assets/javascripts/*"],
+      "@mock/*": ["tests/mocks/*"]
+    },
     "preserveConstEnums": true,
     "removeComments": true,
     "sourceMap": true,